Drier



w' -Jllrl 5,1934. c. w. KEATLEY` Er-Al.

DRIERv iled Feb. 21. 1931 3 Sheets-.Sheet 2 0000 Zaoaa 0000 Jun 5, 1934.c. w. KEATLEY Erm` A 1,961,226

s sheets-sheet s Patented June 5, 1934 DRIER Charles W. Keatley, CastleShannon, Guy V.

Woody, Mount Lebanon, and Collier H. Kear, Dormont, Pa., assignors toKoppers-Rhcolaveur Company, a corporation of Delaware ApplicationFebruary 21, 1931, Serial No. 517,446

20 Claims.

This invention relates to driers of the type disclosed in Patent No.1,650,427 granted November 22, 1927 to Howard B. Carpenter, and thepresent invention has been developed in. order to simplify and improvethe construction and operation of this type of drier.

One object of the invention is to decrease the air or wind resistance ofthe rotary screen, thereby reducing the amount of power required fordriving the same.

Another object is to provide improved sealing joints between the rotaryscreen and stationary parts of the casing to prevent the escape ofmaterial between the casing and the screen.

Still another object is to provide means for retaining on the screenplates` a pad or bed of the material being dried.

A further object is to prevent excessive wear of the casing 4due to theimpact of the material finally dischargedfrom the rotary screen.

A still further object to improve the construction and operation of theefiluentdischarge sluice-way.

/Other objects and features of novelty will be apparent as the followingdescription proceeds, reference being had to the accompanying drawings,in which y Figure l is a view largely in section 'and partly inelevation of a drier embodying the improvements according to the presentinvention;

Fig. 2 is a detail section showing the preferred embodiment of thesealing joint between the feed hopper and the rotary screen;

3 is a'detail section showing the improved sealing arrangement for thebottom of the screen, and the wear plate for receiving the impact of theparticles;

Fig. 4 is an enlarged detail section through the rotary screen adjacent-one of the reinforcing ribs, showing the improved arrangements for decreasing the wind resistance, and for mounting the screen plates andmaterial retaining flange;

Fig. 5 is a top plan view of the structure shown in Fig. 4; Fig. 6 is abottom plan view of the same;

Fig. 7 is a vertical section through the-v outer wall of the casing; e l

Fig. 8 is a. detail of the supporting member which carries the screenplates and the material retaining flange;

Fig. 9 is a section taken along the line IDI-' lX of Fig. 8:

Fig. 10 is a detail of the material retaining flange;

Fig. 11 is an enlarged detail section through being bolted to the lugs30 and the adjacent portions of the hopper and rotary screen, showing amodified hopper sealing means, and the mounting of the upper screenplate; and Fig. 12 is a view similar to Fig. 3, showing the arrangementfor retaining an impact cushioning bed of material on the casing walladjacent the bottom of the rotary screen, as a modified expedient forpreventing excessive wear.

Referring more particularly to the drawings, the drier disclosed in Fig.1 comprises essentially a stationary casing 10 and a rotary screen 1l.In the form shown, the casing 10 comprises a top member 12 which forms acover for the casing, and is provided with a hopper 13. Below the top12, flanged and bolted thereto is an outer side wall 14.

Within the side wall 14 is mounted an inner wall 15 which is spacedtherefrom by a flange 16. bolted to a corresponding ange on the outerWall 14. Below the fiange 16, the inner wall is flanged andbolted to theupper flange of a supporting member for the entire structure. Thismember is preferably a channel 17, although an I-beam structure may beused in some installa.s tions. At this point is secured the top of adischarge chute 18 which delivers the dried material to a conveyor 19.

For supporting and rotating the' screen 11 a vertical shaft 2'0 isprovided, 'the upper end of which is mounted in a conventional bearingnot shown, and provided with suitable driving means. A lower bearing 22`is being carried by a spider ,23, the outer ends .of which are boltedas at 24 to 'internal lugs of. the inner casing wall 15.

I'he rotary screen 11 comprises upper and low- 90 er spiders 27 and 28,which are keyed to the shaft 20. 'The arms of the upper spider 27terminate in a conical rim 29, having peripheral lugs 30. 'I he lowerspider 28 is keyed to the shaft -20 slightly above the bearing 22. 'I'heends of the spider 95 arms carry a lower base ring 32, being preferablycast integral therewith.

'Ihe peripheries of the spiders 27 and 28 are connected by a pluralityof rib members 34, ar-- ranged generally in the form of a pyramid, beingdisposed-in spaced relation. The ends of the rib members 34 terminate inpads 35, the upper pad lower pad being bolted to the rim 3 2.. V 1'05The rib members 34 are provided with offsets 37 4 Itherein, whichoffsets give the rib members al .stepped conguration. In cross-section,the rib members 34 are preferably T-shaped, the flanges of the rotaryscreen, and the web thereof projecting radially outwardly therefrom.

Fitted to the inner side of the rib members 34,

labove and below the offsets 37, are a plurality of screen plates 39.While various kinds of foraminous material may be employed for thispurpose, perforated chromium alloy steel plates have been found verysatisfactory in operation.' The screen plates 39 are frusto=conicalsections, and when fitted to the ribs 34 in the manner described above,these plates 39 form a series of stepped frusto-conical screens.

The entire screen surface and the load of material carried thereby, aresupported by the rib members 34 which span the space between the upperand lower spiders of the rotor. 'I'he rotary screen develops a very highspeed during the drying process, and the consequent centrifugal forceresults in a heavy load on the ribs 34 acting as beams. For this reason,the web of the T section thereof has heretofore been made very deep.This is undesirable, as the depth of this web projects transversely tothe direction of rotation and results in an enormous wind resistance tothe rotation of the screen.

In order to decrease the depth of this flange 36 and thereby decreasethe wind resistance, without sacrificing the strength necessary towithstand the centrifugal force developed, there has been provided aplurality of reinforcing rings -40. The mounting of these members isshown in detail in Figs. 4 and 5 as being associated with thecorresponding offsets 37 in the rib members.

Being continuous around the rotor, these rings reinforce the rib membersto such an extent that the depth of the web 36 may be materiallydecreased, the load heretofore taken thereby being taken by tension inthe ring members 40. The

web 36 is notched as at 42 to receive the ring 440l and this web is alsobossed as at 43 to receive a retaining bolt 44 for the ring.

For supporting the screen plates 39, members 45 are carried by the ribs34, extending between corresponding offsets 37 in the ribs 34. Details.4 of a member 45 are shown in Figs. 8 and 9. This member is preferably acasting in the form of a Z-bar, having flanges 46 and 47 connected by aweb 48. The Z-bar member is curved in such a manner that the flanges 46and 47 and web 48 thereof are conical surfaces. The ends of the flanges46 and 47 are notched away, leaving the web projecting at each end, asat 49.

The portions 49 are fitted under the offsets 37 and secured by screws 50to the flanges ofthe T ribk 34, the notched portions of the flanges 46and 47 serving to clear the flanges of the Trib. The inner upper flange47 forms a base to which is secured, by means of bolts'51, the lowermargin of the screen plate 39 above the offset 37.

'I'he lower outer flange 46 forms a base to which is`secured the uppermargin of the screen plate 39 therebelow by means of bolts 52. Thus themember 45 serves as a rigid supporting base and attaching means for theadjacent screen plates 39.

The member 45 also serves as a support for a retaining flange 53 offsets37. This flange serves to retain a pad qr bed of material thereabove onthe screen plate. This pad of material has' several important functions.

There has been a tendency for the liquid to flow on down the inside ofthe conical screen, instead of passing therethroug The pad of ma-'terial above'the flange 53 absorbs the water and thus retains the same,to

associated with each of the facilitate vthe action of centrifugal forcein causing the water to be forced through the perforations.

Furthermore, the pad of material retained by the flange 53 acts as afilter bed to retain the fines and thus improve the separation. This padof material also acts to cushion one screen against impact thereagainstof material from a screen thereabove, and serves to protect the screenplate from consequent rapid wear.

The member 45 provides a very convenient means for attaching the flange53. As shown in detail in Fig. 10, this fiange 53 is-notched as at 54 toreceive bolts 55 whereby the fiange is adjustably secured to the web 48of the Z-bar 45. Thus the flange 53 may be moved in or out as desired,in order to adjust the depth of the cushioning bed of material retainedon the screen 39.

Intermediate the flanges 53, smaller annular angles 56 are secured tothe screening material in any desired manner, as by bolting, riveting orwelding, and they serve to retain smaller beds of material for the samepurposes. These angles also reinforce the screenbetween the supports 45.

With driers of this type heretofore employed,

. there has been considerable leakage between the hopper 13 and theupper spider rim 29 of the screen. The centrifugal force developed hashad a tendency to project the material received from the hopper 13 outthrough the space between the hopper and the rim 29.

To improve this condition, there has been developed the structure shownin detail in Figs. 2 and 11. The form shown in Fig. 2 is preferred, butthe modification shown in Fig. 11 effectively prevents any leakage.

As shown in Fig. 11, a conical plate 57 is secured by screws 58 to thebottom of the hopper 13. The hopper 13 being conical, the plate 57 isnormal thereto at all points, forming an annular groove, which conformsto the upper rim of the screen element.

The hopper part 13 fits over, and the plate 57 snugly underlies theupper edge of the rim 29 and extends therebelow a sufllcient distance toprevent escape of material fed by the hopper 13. Thus the clearancebetween the parts is so arranged that the direction of action of thecentrifugal force is opposed to the direction of movement of thematerial necessary for the escape thereof. i

'I'he preferred form shown in Fig. 2 preserves all of the advantagesmentioned above, and also facilitates assembly of the machine. In lieuof the plate 57, a ring member 59 is provided, which has a cylindricalface engaging a cylindrical face vertical adjustment of the sealingflange, the bolt holes being enlarged'or elongated for this purpose.'I'hus a uniform'and accurate clearance may be maintained after themachine is -assembled.

As shown in detail in Fig.- 3, an improved ar- -rangement is providedfor sealing the joint between the bottom of the rotary screen and thependicular to the direction of action of the centrifugal force. The web61 of the rim 32 not only 4of the hopper 13. This arrangement permitsserves to improve the seal with the casing Wall 15, but also serves asan abutment to support the lower edge of the screen plates 39. Thescreen plates 39 are notched out to clear the ends of the spider arms 31where theyvjoin the rim 32.

The wear due to impact of particles under the great amount ofcentrifugal force developed in this type of drier has been detrimentalto portions of the casing. One expedient for protecting the casing isshown in Fig. 12. A flange 624 projects inwardly from the casing wall 16a short distance below the flange 60 and forms an annular chambertherebetween. This chamber is intended to receive material thrown oil.the lower.

edge of the screen plate 39, and retain a sufficient amount thereof toform a cushioning bed, so that the impact of later particles will notresult in serious wear upon the casing wall 15.

The preferred construction for contending with this condition is shownin Fig. 3. In lieu of the flange 62, wear plates 63 of harder metal areprovided, which form a liner for the casing wall 15 below the flange 60.

The inner surfaces of the wear plates are smoothly rounded so as vtodeflect the material downwardly toward the d'scharge chute 18. Theplates 63 are secured to the wall 15 by bolts 64. The segmentalconstruction thus afforded facilitates installation and replacement ofthe protective liner formed thereby.

The structure shown in Fig. 7 facilitates th removal of the eilluentmaterial from the casing after it has been thrown off by the screen. Thelower portion of the outer casing wall 14 is conical as shown at 65, andas the inner cas'ng wall l5 is vertical, this tapering of the outer wall14 results in a restricted channel at the bottom of the chambertherebetween.

Furthermore, the conical portion 65' carries a plurality of inwardlyprojecting spiral flanges 66, each of which begins at a thin' edge 67 atthe bottom of the wall 14 and extends upwardly along the portion 65 to ahigh point 68. From the point 68 the flange depends vertically as at 69leaving a space 70 between the portion 69 `and the adjacent edge 67 ofthe next flange. There are fourflanges 66 equally spaced around theinner face of the outer casing wall 14.

In view of the tapered character of the conical portion 65, the spiralflange is Wider at the high portion 68 than at the lower edge 67. Thusthe channel formed by the portion 65, spiral flange 66 and the outersurface of the inner Wall 16 is restricted in two directions. materiallyincreases the velocity of travel of eiiluent material to the space '70which forms a discharge aperture. Below each aperture 70 a dischargechamber 71 is provided for connection to a discharge pipe 72. i

The increase in velocity due to the tapering passage is importantinasmuch as the effluent liquid generally contains a certain amount ofsludge which would tend to clog the passage without this increasedvelocity provision. If extraordinary conditions demand further aid inthe discharge of the effluent material, water pipes 73- are in thenature of improvements on a known` type of drier, nevertheless theimprovements are of' major importance inasmuch as they determine thecommercial success or failure of the This construction.

drier. Furthermore, the various improvements cooperate with each otherin such manner as to greatly improve the Whole. Therefore, while theimprovements have been described in considerable detail, the scope ofthe invention is not to be limited to the exact details disclosed, butinstead embraces such embodiments of the dis- 4fall within the scope ofthe ap-Y closed ideas as pended claims.

We claim as our invention':

1. In a drier, a downwardly and outwardly ta-v pering rotaryfrusto-conical screen, and an annular flange projecting inwardly fromsaid screen and adapted to retain on said screen a bed of the materialbeing dried the inner end of sad flange being normal to said screen.

2. In a drier, a rotary screen comprising downwardly stepped surfaces ofscreening material, anda flange for retaining a bed of material on oneof said screen surfaces to cushion the impact of the material dischargedthereon from another screen surface, the inner end of said flange beingnormal to said screen.

3. In a drier, a rotary screen comprising rib members having offsetportions formed therein, annular reinforcing rings connecting saidoffset portions, and screening material rigidly secured to andreinforced annularly by said reinforcing rings.

4. In a drier, a rotary screen comprising rib members having offsetportions formed therein, annular reinforcing rings connecting saidoffsei portions, and frusto-conical screening material rigidly securedto and reinforced ann'ularly by said reinforcing rings` between ribmembers and between said offset portions.

5. In a drier, a rotary screen comprising an upper rim, a lower rim, ribmembers connecting said rims and having offsets formed therein, annularmembers connecting corresponding offsets of adjacent rib members,frusto-conical screen plates secured to adjacent annular members, aflange projecting inwardly normal to said'screen plate, and anadjustable mounting for said flange on one of said annular members topermlt adjustment of the inward projection thereof.

6. In a drier, a stationary casing part, a rotary frusto-conical screenpart mounted to rotate therein, one of said parts having an annulargroove, and the other part having an annular rim conforming to saidgroove, wherebythe clearance therebetween is transverse to the directionof centrifugal force due to rotation of said screen part, and means foradjusting one of said parts to conform to the other of said parts.

7. In a drier, a stationary frusto-conical hopper, a rotaryfrusto-conical screen and an annular member carried by said hopper andhaving a flange underlying the upper rim of said rotary screen, saidannular member being adjustable from the exterior of said hopper andscreen.

8. In a drier, a rotary screen having an annular rim and a casing havingan inwardly projecting ange underlying said rim, said casing having asecond inwardly projecting flange spaced therebelow and definingtherebetween a chamber for retaining a shock absorbing cushioning bed ofmaterial being screened therein between the casing and the annular rimin the path of subsequent material discharged therefrom.

9. In a drier, a chamber having an annular wall, the lower portion ofsaid wall being conical and provided with an inwardly directed spiralflange decreasing in widthv towards the bottom of the spiral as saidconical wall decreases in bottom of the spiral to eiect an accelerationin 1 velocity of effluent llowing therethrough.

10. In a' drier, a rotary screen, a casing having inner and outerannular walls,'said inner wall having an inwardly directed flangeprojecting into an annular groove in the lower Vrim of said screen, anda ange therebelow forming there with a material retaining chamber, oneof said walls having spiral anges each extending to the other wall andforming .therewith an annular series of efuent sluice-waysl havinginclined bottoms, with discharge ports at their lower ends, and one ofsaid walls being conical and thereby gradually narrowingv thesluice-ways so as to decrease their cross-sectioned area towards thedischarge ports to increase the rate of flow of eiliuent along theflanges.

11. In a drier, a rotary screen, a casinghaving inner and outer walls,said inner wall having an inwardly directed ange in sealing engagementwith the lower edge of said rotary screen, one of said walls having aspiral flange extending to the other wall and forming therewith aneilluent sluice-way having an inclined bottom, and means for directing ajet Aof fluid onto said spiral ange to wash down sludge thereon.

12. In a drier, a casing, a rotary frusto-conical screen in said casingcomprising upper and lower rims, rib members connecting said rims andhaving offset portions therein, annular elements connecting said offsetportions, frusto-conical screening material carried by said annularelements between said rib members and between said oiset portions,annular flanges adjustably secured to said annular elements andprojecting inwardly therefrom normal to said screening material toretain a bed of material thereon,

annular reinforcing rings outsidei ofwsaid rib members and securedthereto adjacent said olfi sets, and means for preventing escape of thematerial being dried between said screen and the adjacent rims ofsaidcasing.

13. In a drier, a rotary frusto-conical screen comprising an uppercircular rimfa larger circular lower rim, and rib members connectingsaid rims and converging toward said upper rim, `said rib members having-offset portions in a plane parallel to said rims, and a reinforcingring secured to the upper outer side of said offset portions.

14. In a drier, a rotary frusto-conical screen comprising an uppercircular rim, a larger circular lower rim, and rib members connectingsaid rims and converging toward said upper rim, said rib members havingoffset portions in a plane parallel to said rims, an annular memberconnected to the underside of the -oset portions of two adjacent ribmembers, an inwardly projecting'ange secured to said, annular member andhaving slots therein, and means passing through said slots foradjustably securing saidange to said annular' membe 15. In a drier, arotary frusta-conical screen comprising an upper circular rim, a largercircular lower rim, and rib members connecting said rims and convergingtoward said upper rim, said rib members having oiset portions in a planeparallel to said rims, an annular member connecting the oisets ofadjacent rib members, an upper screen plate secured to the inner side ofsaid annular member, and a lower screen plate secured to-the outer` sideof said annular member.

16. In a drier, a rotary frusto-conical screen comprising'an uppercircular rim, a larger circular lower rim, and' rib members connectingsaid rims and converging-toward said upper rim, said rib members havingoiset portions in a plane parallel to said rims, a ring secured to theupper side of said offset portions, and an annular member secured to theunder side of said offset portions.

17. In a drier, a rotary frusto-conical screen comprising an uppercircular rim, a larger circular Alower rim, and rib members connectingsaid rims and converging toward saidupper rim,

. screening material secured within said rib members, an annular anglehaving a flange secured to said screening material and another angeprojecting inwardly normal to the surface of said screening material toretain a pad of material being screened thereon over which othermaterial being screened may pass on down the screen and thereby providefor absorbing any liquid that tends to escape centrifuging and run downthe screen. a

18. In a drier, a rotary screen comprising an upper circular rim, alower larger circular rim, rib members connecting said rims and havingoilset portions, a ringsecured to the upper side of said offsetportions, anda Z-bar connecting the adj acentrib members.

'upper circular rim, a. lower larger circular rim, rib membersconnecting said rims and having oiset portions, a ring secured totheupper side of said oiset portions, and a Z-bar connecting theunderside of corresponding offset portions of adjacent rib members andscreening material secured to a ilange of said Z-bar.

20. In a drier, in combination, a rotary frustoconical screen comprisingan upper circular rim, a larger circular lower rim, and rib membersconnecting said rims and converging toward said upper rim, a casingcomprising a hopperin sealing engagement Awith said upper rim, -an innerwall in sealing engagement with said lower rim,

19. In a drier, a rotary screen comprising an and an outer wallconnected to said hopper and said inner wall, one of said walls having aspiral flange tapering in width and downwardly inclined towards a loweroutlet end and extending to the other wall and forming thereby asluiceway of gradually diminishing cross-sectional area towards theouter end.

, CHARLES W. KEATLEY.

